High Angular Resolution Imaging

Reaching the highest possible angular resolution with astronomical instruments is one of the keys to improve our understanding of many astrophysical processes, such as the formation and evolution of planetary systems. In this context, the main goals of our team are to get the most out of the current generation of optical/infrared high-angular resolution instruments and to prepare for the next generation. We are therefore involved in observational programmes at the world’s most advanced optical observatories (VLT, Keck, CHARA, Palomar, etc), as well as in instrumental developments in the fields of interferometry and coronagraphy.

In 2013, the VORTEX project was seriously boosted by two major grants: a Starting Grant from the European Research Council (PI: O. Absil) and an ARC grant from the University of Liège (PI: J. Surdej). The project now employs several graduate students and postdocs. Its main goal is to develop, test (in the lab and on sky), and validate the optical elements and observing techniques that could enable the characterization of Earth-like planets in the habitable zone of nearby stars, either with extremely large ground-based telescopes or dedicated space missions. Check out the Research link for more information on the current activities within the VORTEX project.

Furthermore, in order to facilitate the involvement of Belgian astronomers in current and future programs dealing with high angular resolution direct imaging (e.g., guaranteed time observations at the VLTI), we regularly organise in Liège an introductory course in optical interferometry
Lectures No 1 - 4 (pdf files + videos:mov, avi) given by Jean Surdej (in french):
Introduction to optical/IR interferometry, lectures presented at the 2013 VLTI school "High angular resolution for stellar astrophysics, stellar activity, surface dynamics, fundamental parameters, exoplanetary systems, pulsations", Barcelonnette (France), (in english)
As a follow-up of these introductory courses, specialists in interferometry and future space missions from all over Europe deliver in Liège and in other Belgian astronomical institutions somewhat higher level courses and seminars, which cover all aspects (science, hardware, software, ...) in high angular resolution imaging from the ground and from space.

Our research interests :

The scientific interests of the HARI group are mainly oriented towards extrasolar planetary systems, and in particular

  • proto-planetary disk imaging
  • exozodiacal disks and debris disks
  • extrasolar planet detection and characterisation by direct imaging

Our instrumental research is particularly focused on the development and exploitation of high dynamic range instruments working at high angular resolution, both on the ground and in space, such as:
  • optical/infrared interferometers
  • nulling interferometers
  • coronagraphs

We are also involved in the promotion of optical interferometry within the European astronomical community.

For more information, see our Science page.

The most recent papers by the Liège AEOS group dedicated to High Angular Resolution studies are listed hereafter:


Extragalactic Astrophysics and
Space Observations
Institut d'Astrophysique et de Géophysique, Liège University, Allée du 6 Août, 17 (Sart Tilman, Bât. B5c), 4000 Liège, Belgique Tel.: 04.366.97.55, Fax: 04.366.97.46
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